/*=========================================================================
 *
 *  Copyright NumFOCUS
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *         https://www.apache.org/licenses/LICENSE-2.0.txt
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 *=========================================================================*/

#include <iostream>
#include <cstdlib>
#include "itkSmartPointer.h"
#include "itkMacro.h"

class itkTestObject
{
public:
  using Pointer = itk::SmartPointer<itkTestObject>;
  static itkTestObject::Pointer
  New();
  virtual void
  Register()
  {
    std::cout << "Register " << *this << " count:" << (m_ReferenceCount + 1) << "  " << std::endl;
    m_ReferenceCount++;
  }
  virtual void
  UnRegister()
  {
    std::cout << "UnRegister " << this << " count:" << (m_ReferenceCount - 1) << "  " << std::endl;

    m_ReferenceCount--;
    if (m_ReferenceCount == 0)
    {
      delete this;
    }
  }
  friend inline std::ostream &
  operator<<(std::ostream & os, const itkTestObject & o)
  {
    os << "itkTestObject " << (const void *)&o << ' ' << o.m_ReferenceCount;
    return os;
  }

  std::ostream &
  Print(std::ostream & os) const
  {
    os << "itkTestObject " << (const void *)this << ' ' << this->m_ReferenceCount;
    return os;
  }

protected:
  itkTestObject()
  {
    m_ReferenceCount = 0;
    std::cout << "construct itkTestObject " << *this << std::endl;
  }
  virtual ~itkTestObject() { std::cout << "destruct itkTestObject " << *this << std::endl; }

private:
  unsigned int m_ReferenceCount;
};

itkTestObject::Pointer
itkTestObject::New()
{
  return { new itkTestObject };
}

class itkTestObjectSubClass : public itkTestObject
{
public:
  using Pointer = itk::SmartPointer<itkTestObjectSubClass>;
  static Pointer
  New();
};


itkTestObjectSubClass::Pointer
itkTestObjectSubClass::New()
{
  return { new itkTestObjectSubClass };
}

// This SHOULD NOT be used in ITK, all functions
// should take raw pointers as arguments
void
TestUpCastPointer(itkTestObject::Pointer)
{}

// Test a function that takes an itkTestObject raw pointer
void
TestUpCast(itkTestObject *)
{}


int
itkSmartPointerTest(int, char *[])
{
  // Create a base class pointer to a child class
  const itkTestObject::Pointer to(itkTestObjectSubClass::New());
  // test the safe down cast and create a child class Pointer object
  const itkTestObjectSubClass::Pointer sc = dynamic_cast<itkTestObjectSubClass *>(to.GetPointer());
  // Test the up cast with a function that takes a pointer
  TestUpCast(sc);
  // Test calling a function that takes a SmartPointer as
  // an argument, note, that you have to get the raw pointer
  // for this to work
  TestUpCastPointer(sc.GetPointer());

  // This will not work, but only in construction
  // itkTestObject::Pointer p = sc;

  // For construction use the constructor call:
  // Test casting up the tree, note no explicit cast is required
  itkTestObject::Pointer p(sc);

  // No cast is required for assignment
  p = sc;

  std::cout << "second test" << std::endl;
  {
    auto o1 = itkTestObject::New();
    std::cout << "o1 " << &o1 << std::endl;
    auto o2 = itkTestObject::New();
    std::cout << "o2 " << &o2 << std::endl;
    auto o3 = itkTestObject::New();
    std::cout << "o3 " << &o3 << std::endl;
    auto o4 = itkTestObject::New();
    std::cout << "o4 " << &o4 << std::endl;

    o1 = o2;
    o2 = o3;
    o4 = o1;
    if (o1 < o2)
    {
      std::cout << "o1 is < o2 " << o1 << ' ' << o2 << std::endl;
    }
    else
    {
      std::cout << "o1 is not < o2 " << &o1 << ' ' << &o2 << std::endl;
    }
  }
  std::cout << "end second test" << std::endl << std::endl;


  // check test of null pointer
  itkTestObject::Pointer q(nullptr);
  std::cout << q;

  std::cout << "first test" << std::endl;
  {
    auto o1 = itkTestObject::New();
    if (o1.IsNull())
    {
      return EXIT_FAILURE;
    }

    // use argument dependent loop up for swap in itk namespace
    swap(q, o1);
  }
  std::cout << "end first test" << std::endl << std::endl;
  return EXIT_SUCCESS;
}
